GB2571780A - Trailer detection system for a vehicle - Google Patents

Trailer detection system for a vehicle Download PDF

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Publication number
GB2571780A
GB2571780A GB1803799.4A GB201803799A GB2571780A GB 2571780 A GB2571780 A GB 2571780A GB 201803799 A GB201803799 A GB 201803799A GB 2571780 A GB2571780 A GB 2571780A
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GB
United Kingdom
Prior art keywords
vehicle
sensor
trailer
wheel assembly
displacement
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB1803799.4A
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GB2571780B (en
GB201803799D0 (en
Inventor
Andreas Josephine Kees Donatus
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ford Global Technologies LLC
Original Assignee
Ford Global Technologies LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ford Global Technologies LLC filed Critical Ford Global Technologies LLC
Priority to GB1803799.4A priority Critical patent/GB2571780B/en
Publication of GB201803799D0 publication Critical patent/GB201803799D0/en
Priority to DE102019104378.6A priority patent/DE102019104378A1/en
Priority to US16/288,617 priority patent/US20190276038A1/en
Priority to CN201910164742.0A priority patent/CN110243459A/en
Publication of GB2571780A publication Critical patent/GB2571780A/en
Application granted granted Critical
Publication of GB2571780B publication Critical patent/GB2571780B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D63/00—Motor vehicles or trailers not otherwise provided for
    • B62D63/06—Trailers
    • B62D63/08—Component parts or accessories
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60D—VEHICLE CONNECTIONS
    • B60D1/00—Traction couplings; Hitches; Draw-gear; Towing devices
    • B60D1/58—Auxiliary devices
    • B60D1/62—Auxiliary devices involving supply lines, electric circuits, or the like
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60D—VEHICLE CONNECTIONS
    • B60D1/00—Traction couplings; Hitches; Draw-gear; Towing devices
    • B60D1/01—Traction couplings or hitches characterised by their type
    • B60D1/06—Ball-and-socket hitches, e.g. constructional details, auxiliary devices, their arrangement on the vehicle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60D—VEHICLE CONNECTIONS
    • B60D1/00—Traction couplings; Hitches; Draw-gear; Towing devices
    • B60D1/58—Auxiliary devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
    • B60G17/019—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the type of sensor or the arrangement thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
    • B60W40/10—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to vehicle motion
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
    • G01B21/02—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
    • G01B21/22—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring angles or tapers; for testing the alignment of axes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/30—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H17/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves, not provided for in the preceding groups
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P13/00—Indicating or recording presence, absence, or direction, of movement
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
    • B60G2400/90—Other conditions or factors
    • B60G2400/97—Relation between towing and towed vehicle, e.g. tractor-trailer combination
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2300/00—Indexing codes relating to the type of vehicle
    • B60W2300/14—Tractor-trailers, i.e. combinations of a towing vehicle and one or more towed vehicles, e.g. caravans; Road trains
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2520/00—Input parameters relating to overall vehicle dynamics
    • B60W2520/22—Articulation angle, e.g. between tractor and trailer
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Transportation (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Vehicle Body Suspensions (AREA)

Abstract

A trailer detection system for a vehicle 1 comprises a first sensor, which may be a contactless proximity sensor or a contact sensor, detecting at least one of a vertical and a lateral displacement of a vehicle body relative to at least one wheel assembly 8, 10 of vehicle 1. A processor is configured to process the detected displacement and to determine whether a trailer 3 is connected to vehicle 1. Typically, first sensors may be provided at wheels 8 on one axle and second sensors at wheels 10 on another axle. The determination may involve use of a fast Fourier transform (FFT) to calculate the frequency of oscillation of vehicle 1 and determine if this indicates if trailer 3 is connected.

Description

Trailer detection system for a vehicle
Technical Field
The present disclosure relates to a trailer detection system and is particularly, although not exclusively, concerned with using a plurality of sensors to sense the displacement of a front wheel assembly from a vehicle body and a rear wheel assembly from the vehicle body, and using the instantaneous displacement values at each wheel assembly to infer whether a trailer is attached to the vehicle body.
Background
Vehicle systems such as braking, steering or suspension systems, are typically configured to be optimal for the forces on the vehicle in normal use, such as friction from the wheels of the vehicle and air resistance resulting from the shape and size of the vehicle. However, when a vehicle is towing a trailer, additional forces are also applied to the trailer, and transmitted to the vehicle via means such as a tow bar. These additional forces affect handling of the vehicle, and can also affect the effectiveness of braking, steering and suspension, rendering the vehicle less safe to drive. Vehicle systems such as the brake system may be adjusted by altering the front to rear brake balance and vehicle stability algorithms to compensate for the additional forces caused by the trailer on the vehicle, thus achieving a safer operation of the vehicle. It is therefore advantageous for a vehicle to be able to reliably detect when a trailer is being towed, so vehicle systems can be adjusted accordingly.
Various methods have been used to indicate if a trailer is connected to the tow bar of a vehicle, such as methods which identify additional energy consumption from lights on the trailer and infer that a trailer must therefore be connected to the vehicle. However, these methods are often unable to reliably determine if a trailer is connected to the vehicle, and may be falsely triggered by use of other attachments such as light boards used with a rear mounted bike rack. This may result in an inaccurate compensation of vehicle systems, which could make the vehicle less safe. It is therefore desirable for a vehicle to be able to detect the presence of a trailer with a very high level of accuracy.
Statements of Invention
According to an aspect of the present disclosure, there is provided a trailer detection system for a vehicle, the detection system comprising:
a first sensor configured to detect at least one of a vertical and a lateral displacement of a vehicle body relative to at least one wheel assembly of the vehicle; and a processor, configured to process the detected displacement and to make a determination as to whether a trailer is connected to the vehicle.
The detected displacement may be compared to a threshold value by the processor. The threshold value may be a predetermined value that indicates that a trailer is connected to the vehicle.
When the sensor is measuring vertical displacement at a front axle of a vehicle, the threshold displacement may be greater than a normal range of operational displacement of the vehicle body relative to the at least one wheel assembly of the vehicle without a trailer attached.
When the sensor is measuring vertical displacement at a rear axle of a vehicle, the threshold displacement may be less than a normal range of operational displacement of the vehicle body relative to the at least one wheel assembly of the vehicle without a trailer attached.
The processor may perform Fast Fourier Transform analysis in order to make a determination as to whether a trailer is connected to the vehicle.
The Fast Fourier Transform analysis may be used to calculate the frequency of oscillation of the vehicle. The processor may be configured to determine if the calculated frequency of oscillation is indicative of a trailer being connected to the vehicle.
The first sensor may comprise at least one lateral sensor configured to detect the lateral displacement of the at least one wheel assembly relative to the vehicle body.
A second sensor may be provided. The second sensor may be configured to detect at least one of a vertical and a lateral displacement of the vehicle body relative to another wheel assembly associated with a different axle of the vehicle from the first sensor.
The processor may use the displacement measured by the first sensor and the displacement measured by the second sensor to make a determination as to whether a trailer is connected to the vehicle.
At least one of the first sensor and the second sensor may comprise at least one of a contactless proximity sensor and a contact sensor. The contact sensor may be connected to both the vehicle body and the wheel assembly.
The contact sensor may comprise a sensor body and a probe which is able to move relative to the sensor body. The sensor body may be attached to at least one of the vehicle body and the wheel assembly and the probe may be attached to the other of the vehicle body and the wheel assembly.
The probe may be rotatably connected to the sensor body and to at least one of the vehicle body and the wheel assembly. The sensor may be configured to detect rotation of the probe relative to the sensor body. The probe may be rotatably connected by at least one of a hinge or a ball joint.
The sensor may further comprise a potentiometer or a rotation encoder which detects rotation of the probe relative to the sensor body. The probe may be slideably received within the sensor body, and the sensor may be configured to detect translation of the probe relative to the sensor body.
At least one of the first sensor and the second sensor may be configured to detect both the vertical and the lateral displacement of the vehicle body relative to the at least one wheel assembly of the vehicle.
The first sensor may be configured to detect one of the vertical and the lateral displacement of the vehicle body relative to the at least one wheel assembly of the vehicle. At least one additional first sensor may be provided to detect the other of the vertical and the lateral displacement of the vehicle body relative to the at least one wheel assembly of the vehicle.
The second sensor may be configured to detect one of the vertical and the lateral displacement of the vehicle body relative to the other wheel assembly of the vehicle. At least one additional second sensor may be provided to detect the other of the vertical and the lateral displacement of the vehicle body relative to the other wheel assembly of the vehicle.
The wheel assembly may comprise an axle extending across a centreline of the vehicle.
According to another aspect of the present disclosure there is provided a method of performing trailer detection for a vehicle, the method comprising:
using a sensor to detect at least one of a vertical and a lateral displacement of a vehicle body relative to at least one wheel assembly of the vehicle;
processing the detected displacement; and making a determination as to whether a trailer is connected to the vehicle, based on the processed displacement.
The detected displacement may be compared to a threshold value. The threshold value may be a predetermined value that indicates that a trailer is connected to the vehicle.
The method may further comprise making a Fast Fourier Transform analysis in order to make a determination as to whether a trailer is connected to the vehicle.
The Fast Fourier Transform analysis may be used to calculate the frequency of oscillation of the vehicle. The processor may be configured to determine if the calculated frequency of oscillation is indicative of a trailer being connected to the vehicle
The method may further comprise detecting at least one of a vertical and a lateral displacement of the vehicle body relative to another wheel assembly associated with a different axle of the vehicle, and may use the displacement of the wheel assembly and another wheel assembly to determine whether a trailer is connected to the vehicle.
To avoid unnecessary duplication of effort and repetition of text in the specification, certain features are described in relation to only one or several aspects or embodiments of the invention. However, it is to be understood that, where it is technically possible, features described in relation to any aspect or embodiment of the invention may also be used with any other aspect or embodiment of the invention.
Brief Description of the Drawings
For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:
Figure 1 is a diagram showing the forces acting on a vehicle and a trailer;
Figure 2a is a diagram showing the centre of gravity of an unloaded vehicle;
Figure 2b is a diagram showing the centre of gravity of a vehicle carrying a load;
Figure 2c is a diagram showing the centre of gravity of a vehicle towing a trailer;
Figure 3 is a diagram showing the force acting on a trailer and vehicle when the vehicle is turning;
Figure 4 is a diagram showing an example of a sensor for measuring the displacement of a vehicle body relative to a wheel assembly; and
Figure 5 is a diagram showing an example of a sensor for measuring the displacement of a vehicle body relative to a wheel assembly.
Detailed Description
Figure 1a illustrates the forces present when a vehicle 1 is towing a trailer 3. The vehicle 1 itself will, in normal use, have several forces acting against its direction of motion. For example, vehicle air resistance 5, which will depend on the size and shape of the vehicle 1, will act against the motion of the vehicle 1. Vehicle friction 6 caused by the interaction of the wheels 8, 10 with a road 12 will also oppose the motion of the wheels 8, 10, and thus the vehicle 1. The resistance from vehicle friction 6 will be dependent on the weight of the vehicle 1, including any loads carried by the vehicle, in addition to the coefficient of friction between the wheels 8, 10 and the road 12.
As is shown in Figure 1, when a trailer 3 is being towed, similar forces are also applied to the trailer. Air resistance will cause a resultant force on trailer 3. The trailer air resistance 16 will at least partly depend on the shape and size of the trailer. As is also shown in this Figure, trailer friction 18 caused by the resistance of the road 12 to the movement of the wheels of the trailer 20 will also cause a resultant force to be applied against the motion of the trailer. The friction force on the trailer will be dependent on the weight of the trailer and the coefficient of friction between the wheels of the trailer and the road. Forces caused by the presence of a trailer will be transmitted to the vehicle 1 via the tow bar 14. Thus, a vehicle 1 towing a trailer 3 will have its forward motion further opposed at least by additional force caused by trailer air resistance 16 on the trailer 3 and trailer friction 18 caused by the interaction of the trailer wheels 20 with the road 12.
Conventional road vehicles 1 are provided with suspension, which allows a vehicle body 22 to move relative to a wheel assembly 8, 10 of the vehicle. The wheel assembly may comprise one or more wheels fitted with pneumatic tyres rotating about a hub which is suspended from the vehicle body by a suspension assembly. The suspension assembly may comprise leading or trailing arms and a resilient element such as a leaf or coil spring or an air suspension unit. The wheel assembly may be connected to a second wheel assembly by an axle which extends across a centreline of the vehicle.
The additional force applied to the vehicle body 22 via the tow bar 14 when towing the trailer 1 will cause the wheel assembly 8, 10 to move in a forward direction slightly, relative to the vehicle body 22. The forward motion of the vehicle body will be resisted by the air resistance on the vehicle body, but also by the forces which resist forward motion of the trailer. Thus, as the vehicle moves forward, dragging the trailer behind it, the relative movement of the wheel assembly with respect to the vehicle body will cause the wheel assembly to move slightly in a direction towards the front of the vehicle body 22, i.e. there will be a displacement on the y axis between the wheel assembly 8, 10 and the vehicle body 22.
A similar occurrence will result from loading of the vehicle 1. When a vehicle is provided with additional weight, for example by placing additional items into the vehicle, a greater force will be required to accelerate the vehicle body 22. Thus, the additional weight will cause a displacement between the wheel assembly 8, 10 and the vehicle body 22 when the vehicle 1 is accelerating.
The additional forces on a vehicle 1 caused by towing the trailer 3 could result in an equivalent resistance to forward motion of the vehicle 1 as is generated by a vehicle which is heavily laden but is not towing a trailer. In such circumstances, towing the trailer will therefore result in the same net displacement on the y axis of the vehicle body 22 relative to the wheel assembly 8, 10, as is experienced by a heavily laden vehicle. Thus, it would be difficult to distinguish, from the displacement of the vehicle body on the y axis alone, a heavily laden vehicle from a lightly laden vehicle towing a trailer. Detection of displacement on the y axis could therefore provide a determination of whether a trailer is being towed, but would not provide high reliability.
Figure 2a shows the centre of gravity of a typical unloaded vehicle 201. The centre of gravity 224 is located between front 208 and rear 210 wheel assemblies. The vehicle body 222 is suspended relative to the front and rear wheel assemblies 208, 210 and the weight of the vehicle 201 is distributed through the suspension between the front and rear wheel assemblies 208, 210. When the vehicle 201 is loaded, for example with cargo in the rear of the vehicle, as is shown in Figure 2b, the centre of mass 224 of the vehicle 201 will be shifted towards the rear of the vehicle. The additional weight of cargo in the vehicle body will cause the vehicle body to move downwardly, compressing the suspension at the front and rear axles of the vehicle, so that the vehicle body moves closer in a vertical (z axis) direction to the wheel assemblies and to the road.
Figure 2c shows a trailer 203 being towed by the vehicle 201, in a situation where the mass of the cargo carried by the vehicle 201 is approximately equal to the mass of the trailer 203. The mass of the trailer applies a load on the y axis as discussed above. This load is supported by wheels of the trailer and by a tow ball 226 of a tow hitch 214 fixed to the towing vehicle, typically above a wheel centre of a rear wheel assembly 210. The force applied by the trailer on the tow hitch varies dynamically as the towing vehicle and trailer move over an undulating road surface, but for a large stationary trailer on a level road surface, the weight supported by the tow hitch 214 (the tongue weight) is ideally adjusted to about 100 to 150Kg.
Thus, when the trailer 203 is connected to the tow hitch 214 of the vehicle 201, the vehicle 201 partially supports the trailer 203, and the load from the trailer is applied to the towing vehicle to the rear of the rear axle. Consequently, the front of the vehicle will ride slightly higher than it would without a trailer and the rear of the vehicle will ride slightly lower as a result of the down force on the z axis from the trailer onto the hitch 224, causing the vehicle to pivot about the rear axle. As the vehicle moves forward along an undulating road, the down force from the trailer onto the hitch 224 will vary significantly and may even change direction, causing the rear of the vehicle to pitch down as the front of the vehicle rises up, and vice versa.
When the vehicle brakes, the momentum of an unbraked trailer will cause the front of the vehicle to pitch down, but this effect is broadly similar to the braking of a loaded vehicle without a trailer (i.e. a vehicle carrying the cargo on its load bed).
As is shown in Figure 3, when the vehicle 301 turns, so that the trailer 303 and the vehicle 301 are no longer aligned, the trailer continues to apply a force 328 in the direction in which it is attempting to travel. Thus, components of the force 328 on the x axis and the y axis will be applied to the vehicle 301 by the trailer 303. In this situation, the vehicle body 322 is pushed sideways (x axis) as well as forwards (y axis), if the vehicle is decelerating, due to the continuing motion of the trailer. Thus, the vehicle body moves in a lateral and forwards direction relative to the wheel assemblies.
Displacement of the vehicle body relative to the front or rear wheel assemblies when a vehicle is towing a trailer will therefore differ from the displacement resulting from a load being carried on or in the body of the vehicle. As mentioned above, whilst displacement on the y axis is harder to definitively attribute to a load carried on a vehicle or a load towed by a vehicle, displacement of a vehicle body relative to the wheel assemblies of the vehicle in the lateral (x axis) direction or the vertical (z axis) direction may be used to indicate that a trailer is connected to a vehicle. Thus, by measuring the displacement of the vehicle body relative to at least one wheel assembly in at least one of the lateral and the vertical directions and processing the measurement, it is possible to determine if a trailer is connected to the vehicle.
Furthermore, when a trailer is being towed, it can exhibit a forward-backward rocking oscillation which is translated into an up-down movement at the rear of the vehicle via the tow bar. The movement of the vehicle body in a lateral direction (x axis) as well as the up and down movement (z axis) with respect to a wheel assembly can be measured and processed using Fast Fourier Transform (FFT) analysis to separate the frequency of the trailer oscillation from the natural frequency of the vehicle suspension. By performing FFT analysis on a signal produced by a wheel assembly sensor to establish whether there is one or more additional frequency being induced by a trailer, it is therefore possible to determine reliably whether a trailer is connected to the vehicle. The measured displacement of the wheel assembly relative to the vehicle body may therefore be processed by performing FFT analysis to detect oscillation of the vehicle body induced by the trailer and thereby determine whether a trailer is connected to the vehicle.
In a first arrangement shown in Figure 4, a trailer detection system for a vehicle is provided, wherein the detection system comprises a lateral sensor 430 which comprises a first sensor body 432 attached to the vehicle body 422 and a first probe 434 attached at a centre point of an axle 454 of the wheel assembly 408, the first probe 434 being rotatably connected to the first sensor body 432. Similarly, there is provided a vertical sensor 436 which comprises a second sensor body 438 attached to the vehicle body 422 and a second probe 440 attached to the wheel assembly 408, the second probe 440 being rotatably connected to the second sensor body 438.
The vehicle body 422 and the wheel assembly 408 are suspended relative to one another using known vehicle suspension. Thus, motion of the wheel assembly 408 relative to the vehicle body 422 causes the first probe 434 to rotate relative to the first sensor body 432 via a first hinge 442, wherein the rotation of the first hinge 442 corresponds to the motion of the wheel assembly 408. The first hinge 442 is arranged along the y axis so as to rotate in the x-z plane. The first probe comprises a first section 444 and a second section 446, wherein the first section 444 is rotatably connected to each of the wheel assembly 408 and the second section 446, and the second section 446 is further rotatably connected to the fist sensor body 432 via the first hinge 442. The first section 444 extends substantially parallel to the axle 454, and the second section 446 extends substantially parallel to the z direction, when the vehicle is in an equilibrium position (e.g. stationary).
The vertical sensor 436 is configured in a similar way to the lateral sensor. Thus, motion of the wheel assembly 408 relative to the vehicle body 422 causes the second probe 440 to rotate relative to the second sensor body 438 via a second hinge 452, wherein the rotation of the second hinge 452 corresponds to the motion of the wheel assembly 408. The second hinge 452 is arranged along the y axis so as to rotate in the x-z plane. The second probe comprises a third section 448 and a fourth section 450, wherein the third section 448 is rotatably connected to each of the wheel assembly 408 and the fourth section 450, and the fourth section 450 is further rotatably connected to the second sensor body 438 via the second hinge 452. However, in contrast to the lateral sensor, the third section 448 is provided substantially parallel to the z direction, and the fourth section 450 is provided substantially parallel to the axle 454.
Thus, the first hinge of the lateral sensor 430 will rotate more due to lateral components of displacement than vertical components of displacement, and the second hinge of the vertical sensor 436 will rotate more due to vertical components of displacement than lateral components of displacement. Consequently, the rotation of the first hinge 442 due to a lateral and vertical displacement of the vehicle body 422 with respect to the wheel assembly 408 will differ from the rotation of the second hinge 452. By using the values of rotation of the first hinge 442 and the second hinge 452, i.e. by comparing the values in a look-up table, it is possible to determine the lateral and vertical components of the displacement, either of which, or both in combination, can be used to determine if the trailer is connected to the vehicle.
The sensor may comprise a potentiometer or a rotation encoder to detect the rotation of the first and/or second hinge relative to the respective sensor body. The trailer detection system further comprises a processor (not shown) which is configured to process the detected rotation of the first and/or second hinge to determine whether a trailer is connected to the vehicle.
To determine whether a trailer is connected to the vehicle, the detected displacement may be compared to a threshold value by the processor, where the threshold value is a predetermined value that indicates that a trailer is connected to the vehicle. When the sensor is measuring vertical displacement at a front axle of a vehicle, the threshold value of displacement may be greater than a normal range of operational displacement of the vehicle body relative to the at least one wheel assembly of the vehicle without a trailer attached. When the sensor is measuring vertical displacement at a rear axle of a vehicle, the threshold value of displacement may be less than a normal range of operational displacement of the vehicle body relative to the at least one wheel assembly of the vehicle without a trailer attached.
Alternatively, the processor may perform Fast Fourier Transform (FFT) analysis in order to make a determination as to whether a trailer is connected to the vehicle. FFT analysis allows frequencies of different signals to be separated from one another. The Fast Fourier Transform analysis may be used to calculate the frequency of oscillation of the vehicle. The processor may be configured to determine if the calculated frequency of oscillation is indicative of a trailer being connected to the vehicle.
It will be appreciated that the wheel assembly 408 of these examples comprise an axel 454 and two wheels 456a, 456b of the vehicle 401. However, it should be appreciated that the wheel assembly 408 may comprise only one wheel 456a, 456b and a hub of the vehicle. There may be provided between two and four such wheel assemblies on a conventional vehicle. The wheel assemblies may each be suspended independently of one another.
Further sensors may be provided at each independently suspended wheel assembly. At least one sensor may be provided at a rear wheel assembly, and at least one sensor may be provided at a front wheel assembly. Each wheel assembly may be provided with more than one sensor. Thus, a second sensor (not shown) may be provided, where the second sensor may be configured to detect at least one of a vertical and a lateral displacement of the vehicle body relative to another wheel assembly associated with a different axle of the vehicle from the first sensor.
Thus, the processor may use the displacement measured by the first sensor and the displacement measured by the second sensor to make a determination as to whether a trailer is connected to the vehicle. Either the front or rear axel will be displaced from the vehicle body more than the other of the front or rear axel when a trailer is connected to a vehicle. By comparing the displacement of a front and rear axle relative to the vehicle body, it is possible to distinguish a trailer attached to the rear of a vehicle from a load provided within or on the vehicle.
In the second arrangement shown in Figure 5, there is provided an alternative trailer detection system comprising a lateral sensor 530 comprising a first sensor body 532 rotatably mounted to a bracket fixed to the vehicle body 522 and a first probe 534 rotatably mounted attached to a centre point of an axel 554 of the wheel assembly 508. The first probe 534 is able to move relative to the first sensor body 532. The first probe
534 is slideably received within the first sensor body 532, and the lateral sensor 530 is configured to detect a translation of the probe relative to the sensor body. Figure 5 also shows a vertical sensor 536 comprising a second sensor body 538 rotatably attached to the vehicle body 522 and a second probe 540 rotatably attached to the centre point of the axel 554 of the wheel assembly 508. The second probe 540 is able to move relative to the second sensor body 538. The second probe 540 is slideably received within the second sensor body 538, and the vertical sensor is configured to detect a translation of the probe relative to the sensor body.
It will be appreciated that displacement of the vehicle body with respect to the wheel assembly in either the vertical or lateral direction will result in displacement of either probe relative to their corresponding sensor body. In the lateral sensor, lateral displacement will result in a greater displacement of the first probe relative to the first sensor body than that of the second probe relative to the second sensor body. For vertical displacement, the reverse will be true. Thus, the displacement of the first probe relative to the first sensor body and the displacement of the second probe relative to the second sensor body will usually differ for the same overall displacement of the vehicle body with respect to the wheel assembly. Thus, the two detected displacements can be used to determine the lateral and vertical components of displacement of the vehicle body with respect to the wheel assembly.
A processor (not shown) is configured in the same manner as the processor described in relation to example 1, and is thus configured to process the detected displacement and to make a determination as to whether a trailer is connected to the vehicle. Thus, it is possible to determine whether the trailer is connected to the vehicle using the detected displacement.
It will be appreciated that any sensor may be used which is able to determine a displacement of the vehicle body with respect to the wheel assembly, and the displacement processed in the manner stated herein in order to determine whether a trailer is connected to a vehicle. For example, the distance between a body of a vehicle and a wheel assembly may be measured by a laser distance measurer as is known in the art. A laser distance measurer may be configured to measure the distance between the underside of a vehicle body and a portion of the wheel assembly in a vertical direction. Alternatively or additionally, a laser distance measurer may be configured to measure the distance between a fixed point on the vehicle body and a wheel of the wheel assembly in a lateral direction. Any distance measurement apparatus capable of measuring a distance between the vehicle body and a wheel assembly may be applied.
It will be appreciated by those skilled in the art that although the invention has been described by way of example, with reference to one or more exemplary examples, it is not limited to the disclosed examples and that alternative examples could be constructed without departing from the scope of the invention as defined by the appended claims.

Claims (24)

1. A trailer detection system for a vehicle, the detection system comprising:
a first sensor configured to detect at least one of a vertical and a lateral displacement of a vehicle body relative to at least one wheel assembly of the vehicle; and a processor, configured to process the detected displacement and to make a determination as to whether a trailer is connected to the vehicle.
2. A trailer detection system as claimed in claim 1, wherein the detected displacement is compared to a threshold value by the processor, the threshold value being a predetermined value that indicates that a trailer is connected to the vehicle.
3. A trailer detection system as claimed in claim 2, wherein when the sensor is measuring vertical displacement at a front axle of a vehicle, the threshold displacement is greater than a normal range of operational displacement of the vehicle body relative to the at least one wheel assembly of the vehicle without a trailer attached.
4. A trailer detection system as claimed in claim 2, wherein when the sensor is measuring vertical displacement at a rear axle of a vehicle, the threshold displacement is less than a normal range of operational displacement of the vehicle body relative to the at least one wheel assembly of the vehicle without a trailer attached.
5. A trailer detection system as claimed in any preceding claim, wherein the processor performs Fast Fourier Transform analysis in order to make a determination as to whether a trailer is connected to the vehicle.
6. A trailer detection system as claimed in claim 5, wherein the Fast Fourier Transform analysis is used to calculate the frequency of oscillation of the vehicle, and the processor is configured to determine if the calculated frequency of oscillation is indicative of a trailer being connected to the vehicle.
7. A trailer detection system for a vehicle as claimed in any preceding claim, wherein the first sensor comprises at least one lateral sensor configured to detect the lateral displacement of the at least one wheel assembly relative to the vehicle body.
8. A trailer detection system for a vehicle as claimed in any preceding claim, wherein a second sensor is provided, the second sensor being configured to detect at least one of a vertical and a lateral displacement of the vehicle body relative to another wheel assembly associated with a different axle of the vehicle from the first sensor.
9. A trailer detection system for a vehicle as claimed in claim 8, wherein the processor uses the displacement measured by the first sensor and the displacement measured by the second sensor to make a determination as to whether a trailer is connected to the vehicle.
10. A trailer detection system for a vehicle as claimed in any preceding claim, wherein at least one of the first sensor and the second sensor comprises at least one of a contactless proximity sensor and a contact sensor connected to both the vehicle body and the wheel assembly.
11. A trailer detection system for a vehicle as claimed in claim 10, wherein the contact sensor comprises a sensor body and a probe which is able to move relative to the sensor body, the sensor body being attached to at least one of the vehicle body and the wheel assembly and the probe being attached to the other of the vehicle body and the wheel assembly.
12. A trailer detection system for a vehicle as claimed in claim 11, wherein the probe is rotatably connected to the sensor body and to at least one of the vehicle body and the wheel assembly, and the sensor is configured to detect rotation of the probe relative to the sensor body.
13. A trailer detection system for a vehicle as claimed in claim 12, wherein the probe is rotatably connected by at least one of a hinge or a ball joint.
14. A trailer detection system for a vehicle as claimed in claim 12, wherein the sensor further comprises a potentiometer or a rotation encoder which detects rotation of the probe relative to the sensor body.
15. A trailer detection system for a vehicle as claimed in claim 11, wherein the probe is slideably received within the sensor body, and the sensor is configured to detect translation of the probe relative to the sensor body.
16. A trailer detection system for a vehicle as claimed in claim 8, wherein at least one of the first sensor and the second sensor is configured to detect both the vertical and the lateral displacement of the vehicle body relative to the at least one wheel assembly of the vehicle.
17. A trailer detection system for a vehicle as claimed in any preceding claim, wherein the first sensor is configured to detect one of the vertical and the lateral displacement of the vehicle body relative to the at least one wheel assembly of the vehicle, and at least one additional first sensor is provided to detect the other of the vertical and the lateral displacement of the vehicle body relative to the at least one wheel assembly of the vehicle.
18. A trailer detection system for a vehicle as claimed in claim 8, wherein the second sensor is configured to detect one of the vertical and the lateral displacement of the vehicle body relative to the other wheel assembly of the vehicle, and at least one additional second sensor is provided to detect the other of the vertical and the lateral displacement of the vehicle body relative to the other wheel assembly of the vehicle.
19. A trailer detection system for a vehicle as claimed in any preceding claim, wherein the wheel assembly comprises an axle extending across a centreline of the vehicle.
20. A method of performing trailer detection for a vehicle, the method comprising:
Detecting at least one of a vertical and a lateral displacement of a vehicle body relative to at least one wheel assembly of the vehicle;
Processing the detected displacement; and
Making a determination as to whether a trailer is connected to the vehicle.
21. A method as claimed in claim 20, wherein the detected displacement is compared to a threshold value, the threshold value being a predetermined value that indicates that a trailer is connected to the vehicle.
22. A method as claimed in claim 20, wherein Fast Fourier Transform analysis is performed in order to make a determination as to whether a trailer is connected to the vehicle.
23. A method as claimed in claim 22, wherein the Fast Fourier Transform analysis is used to calculate the frequency of oscillation of the vehicle, and the processor is configured to determine if the calculated frequency of oscillation is indicative of a trailer being connected to the vehicle
24. A method as claimed in claim 20, further comprising detecting at least one of a vertical and a lateral displacement of the vehicle body relative to another wheel assembly associated with a different axle of the vehicle, and using the displacement of the wheel assembly and another wheel assembly to determine whether a trailer is connected to the vehicle
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GB1803799.4A GB2571780B (en) 2018-03-09 2018-03-09 Trailer detection system for a vehicle
DE102019104378.6A DE102019104378A1 (en) 2018-03-09 2019-02-21 Trailer detection system for a vehicle
US16/288,617 US20190276038A1 (en) 2018-03-09 2019-02-28 Vehicle trailer detection system
CN201910164742.0A CN110243459A (en) 2018-03-09 2019-03-05 Trailer detection system for vehicle

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CN112678088B (en) * 2019-10-18 2024-07-09 苏州宝时得电动工具有限公司 Transport system
SE543839C2 (en) * 2019-12-17 2021-08-10 Scania Cv Ab Method and control arrangement for status estimation of a trailer unit

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GB2387582A (en) * 2002-04-12 2003-10-22 Ford Global Tech Llc A vehicle air suspension system including trailer load measurement means
EP2508405A2 (en) * 2011-04-06 2012-10-10 Robert Bosch Gmbh Continuous computation of center of gravity of a vehicle
US20170210193A1 (en) * 2016-01-22 2017-07-27 Ford Global Technologies, Llc System and method for adjusting a motor vehicle chassis
GB2554439A (en) * 2016-09-28 2018-04-04 Jaguar Land Rover Ltd A method for determining the presence of a trailer

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GB2387582A (en) * 2002-04-12 2003-10-22 Ford Global Tech Llc A vehicle air suspension system including trailer load measurement means
EP2508405A2 (en) * 2011-04-06 2012-10-10 Robert Bosch Gmbh Continuous computation of center of gravity of a vehicle
US20170210193A1 (en) * 2016-01-22 2017-07-27 Ford Global Technologies, Llc System and method for adjusting a motor vehicle chassis
GB2554439A (en) * 2016-09-28 2018-04-04 Jaguar Land Rover Ltd A method for determining the presence of a trailer

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GB201803799D0 (en) 2018-04-25

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